Process Tamer changes the priority of apps so that some apps get more cpu cycles from the computer than others every second.

It's a very specific action which serves to make your computer more responsive to your input, by slowing down programs which would otherwise dominate the cpu, OR by doing the opposite -- giving certain programs more of the cpu so that they perform faster, but at the expense of slowing down other programs and the operating system user interface.

This is not magic and it's not a hoax, it's a real feature that can be useful in certain cases.

(The prevalence of superfast multi-core cpus makes tools like Process Tamer less critical than they are on slower single core cpus, because with multiple cores it's not often that your computer will be unresponsive due to a single program hogging the cpu).

Process Tamer has definitely helped me in the past (on a slower machine). I think I used it during video encoding. Anyway, it worked, definitely no placebo involved - it's quite obvious when an old, single core, system isn't very responsive.

To be clear, Process Tamer does not make your computer run faster, nor does it claim to. Given a certain amount of work (say, encode a video), when using software like Process Tamer, your computer will not complete the task any quicker.

What it does do is help the processes running in the system cooperate by (a) assuming that you, while sitting in front of the computer, want to have better responsiveness; and (b) using input you may give it telling it that certain programs don't deserve instantaneous responsiveness. The result is that greedy stuff that would monopolize the system will be prevented from doing so.

In fact, because the system is allowing you to interrupt more readily, the final result may actually be that our hypothetical process takes somewhat longer to complete -- but you'll feel less frustrated during that time.

There's nothing magic, just juggling priorities a bit differently than the system does by default.